Sarah has put up a very thoughtful and insightful set of posts on the highs and lows of being religious (specifically of being an Orthodox Jewish girl). And I envy her. Yes, secular girl here envies both her highs and her lows. Because, being secular - being very, very, very secular - all I really have are those "lows."
Being non-religious is a lonely experience. There is no comfort of feeling like there is a G-d who is looking out for you, caring about what occurs in your life or anyone elses. There is no sense that what you do and how you behave affects anything beyond yourself and those whom you touch, directly or indirectly, through your actions. So I try to be a good person (I don't always succeed) and to do good things, not for G-d's sake but for the sake of the people I share this world with.
Studies have shown that people who believe get a lot of benefits: they live longer, overall they are healthier, in later life they are happier and have more life satisfaction. In short, they are more resiliant, content, and at peace.
I would like to be able to believe. I've tried. I went through a "religious phase" when I was about 14. I went to services at Chabad House, tried to keep halachot (extra difficult while living in a very non-religious household) to the best of my ability, I felt some of those highs, and desperately wanted to believe. But all the time there was the little voice in the back of my mind saying, "Ok, if there is a G-d then why do all these bad things happen and to very good people? If He is not able to stop them from happening, then why bother? If He _is_ able to stop them from happening and for whatever reason chooses not to, then _really_ why bother?"
Now all that said, I'm not an athiest, exactly. I kind of keep one foot in each camp, I guess you would say. I say this only because I've discovered that at times of extreme duress I find myself fervantly praying to this G-d that I'm not sure exists and --if He does --want to give a good piece of my mind to. And I say this because I regularly _do_ give Him a good piece of my mind in my own little private, one-way "conversations." If I totally didn't believe, then...why bother?
I know that I would be happier if I could believe wholeheartedly and thoroughly. I just can't. So I'm left with envying those who can both their highs and their lows.